Device for relative fixing of elements telescopically displaced in each other

ABSTRACT

A locking device for two units ( 1 ), ( 3 ) displaceable one inside the other, such as the handle of an implement with variable length, comprising a locking member ( 4 ) arranged at one end of the outer element ( 3 ), said locking member ( 4 ) being operated by an operating member ( 5 ) spaced from the locking member ( 4 ) in the direction of the other end of the outer element ( 3 ) via an actuating member ( 7 ) that is displaceable along, or turnable about, an axis parallel with the longitudinal axis of the outer element ( 3 ).

PRIOR APPLICATIONS

This is a continuation patent application that claims priority form U.S.national phase patent application Ser. No. 11/549,626, filed 13 Oct.2006 that claims priority from Ser. No. 10/362,767, filed 24 Feb. 2003that claims priority from PCT/SE01/01856, filed 31 Aug. 2001, thatclaims priority from Swedish Patent Application No. 0003117-9, filed 3Sep. 2000.

TECHNICAL FIELD

The invention relates to a device for detachably locking two elements inan optional position in relation to each other, said elements beingtelescopically or turnably movable in relation to each other with acertain clearance between the two elements, such as a rod or pipe withinan outer rod or within an outer sleeve.

BACKGROUND ART

Many types of devices for detachably locking two telescopically movableelements in relation to each other are known, such as simple screwjoints, cotter and hole joints, wedge joints, conical ring joints,eccentric joints, etc. These devices exhibit different properties anddrawbacks.

Cotter and hole joints and other shape-dependent joints (e.g. SE870387-6) provide a secure connection but only allow stepwise adjustmentof the elements in relation to each other. Other joints such as screwjoints, are dependent on friction and thus allow stepless setting, butthey often require such high contact forces to ensure reliable lockingthat the contact surfaces become deformed.

SE 8203018-0 describes a device with an intermediate element 8 to spreadthe contact force over a larger area with the object of avoiding damageto the contact surfaces. A drawback with this device, however, is thatthe locking force is so great that a screw must be used, which is aninconvenience.

EP 0209756 describes a device in which a rubber ring 4 having circularcross section is used as a locking and sealing element. A drawback withthis device, however, is that setting the two elements in relation toeach other is complicated since the joint must be opened and the rubberring rolled to the desired position.

DE 3143793 describes a device in which a plastic washer 40 with aconical end piece is clamped between corresponding conical surfaces onthe outer and inner telescopic elements. A drawback with this, however,is that the fit between the inner telescopic element and the washer mustbe so accurate that it is rather difficult to move it along the innertelescopic element. Another drawback is that the washer is thus subjectto wear.

Common to these known solutions is that they are generally operated bymovement of the operator's hand and that the operation cannot beperformed at a distance from the locking unit. In the use oftelescopically adjustable handles for implements, such as cleaninghandles, particularly cleaning handles for floor care such as floor mopsit is, for ergonomic reasons, extremely necessary to be able to operatethe telescopic function from the upper part of the handle, without theneed for any turning movement. From the ergonomic aspect it is mostadvantageous if control can be performed by means of pressure close tothe upper part of the handle, at right angles to the longitudinal axisof the handle, and for the application of this pressure via acompressive movement of the operator's hand to give rise to release ofthe locking device.

DESCRIPTION OF THE INVENTION

The main object of the present invention is to provide an easilyoperated but, at the same time, extremely reliable device for steplessand detachable locking of two elements that are telescopically orturnably movable in relation to each other. The device shall be usablein widely differing technical areas where the stop positions between twoelements must be changed. The device is primarily intended for thehandles of implements such as cleaning handles, particularly cleaninghandles for floor care, such as floor mops. Other feasible areas ofapplication are e.g. sports equipment, stands, masts and frames.

Another object of the present invention is to provide a device thatpermits adjustment of the position between the inner and outer elementsvia a control spaced from the locking device.

Another object of the present invention is to provide a device thatallows repeated, reliable locking of a desired position between theinner and outer elements without any function-impairing influence orwear occurring on the parts involved.

Yet another object of the present invention is to provide a device thatallows adjustment of the position between the inner and outer elementswithout the need for any turning movement.

These objects are achieved by means of a device for detachably lockingtwo elements in an optional position, said elements being telescopicallyor turnably movable in relation to each other with a certain clearancebetween the two elements, such as a rod or pipe within an outer rod orwithin an outer sleeve, comprising a locking device operated by means ofan operating member spaced from the locking device, via an actuatingmember.

The invention will be described in more detail with reference to theaccompanying drawings, the latter being intended to explain and not tolimit the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view from the side showing the handle of an implement with adevice in accordance with the invention.

FIG. 2 is a partial view, partly in cross-section, in the direction ofthe arrow A in FIG. 1, showing mostly the locking device, in lockedposition.

FIG. 3 is a view B of the device as shown in FIG. 2

FIG. 4 is a view of the device as shown in FIG. 2, when disconnected.

FIG. 5 is a view C of the device shown in FIG. 4.

FIG. 6 is a partial view, partly in cross-section, showing mostly theoperating member.

FIG. 7 is a partial view, partly in cross-section, showing primarily theoperating member in an alternative embodiment.

FIG. 8 is a partial view, partly in cross-section, showing a lockingdevice and an operating member without intermediate actuating member, inlocked position.

FIG. 9 is a partial view, partly in cross-section, showing a device asshown in FIG. 8, when disconnected.

FIG. 10 is a partial view from the front of an embodiment of theinvention where the actuating member is omitted.

FIG. 11 is a partial view from the side, partly in cross-section, of thedevice shown in FIG. 10 in which the device is in a locked position.

FIG. 12 is a partial view as shown in FIG. 11 in which the device is inan unlocked position.

FIG. 13 is a side view from the device where the inner element is turnedto face the operator.

FIG. 14 is a cross-sectional view of the locking member of the deviceshown in FIG. 13.

FIG. 15 is a cross-sectional view of another embodiment of the device ofthe present invention with a locking wedge pressed against wedge-shapedgrooves in the inner element.

FIG. 16 is a cross-sectional view of the embodiment, shown in FIG. 15,in which the device is in an unlocked position.

FIG. 17 is cross-sectional top view of the inner element as shown inFIGS. 15 and 16.

FIG. 18 is a partial side view of an inner element where a number ofrectangular holes are arranged in an axially directed recess.

FIG. 19 is a cross-sectional top view of a locking member in an unlockedposition.

FIG. 20 is a cross-sectional top view of the locking member, shown inFIG. 19, in a locked position.

FIG. 21 is a cross-sectional view of a locking member having atangentially displaceable locking yoke that can act on the surface ofthe inner element.

FIG. 22 is a cross-sectional view of the locking member shown in FIG.21, where the locking yoke is operated by a knob.

FIG. 23 is a partial view from the front of a locking member with a knobacting on the inner element via recesses in the outer element.

FIG. 24 is a partial view of the locking member shown in FIG. 23.

FIG. 25 is a rear view of a contact surface of the knob.

FIG. 26 is a cross-sectional of an inner element and an outer elementwhere the outer element has integrated locking elements.

FIG. 27 is a cross-sectional view of the arrangement shown in FIG. 26where the inner element is locked to the outer element.

FIG. 28 is a partial cross-sectional side view of the arrangement shownin FIG. 26.

FIG. 29 is a cross-sectional view of different embodiments of thelocking elements in the outer element.

FIG. 30 is a front side view of an outer element that has flaps punchedout.

FIG. 31 is a left view of the outer element shown in FIG. 30.

FIG. 32 is a side view of the outer element shown in FIG. 30.

FIG. 33 is a front view of the outer element shown in FIGS. 30-32.

FIG. 34 is a left view of the device shown in FIG. 33.

FIG. 35 is a side view of the device shown in FIG. 33.

FIG. 36 is a front view of an alternative embodiment.

FIG. 37 is a front view of the embodiment shown in FIG. 36 where theoperating member is pressed to lock the inner element relative the outerelement.

FIG. 38 is a front view of the embodiment shown in FIG. 36 where theoperating member is blocked in a locked position.

FIG. 39 is a front view of a locking member.

FIG. 40 is a perspective view of the locking member shown in FIG. 39.

FIG. 41 is a cross-sectional view along the lines A-A of the lockingmember shown in FIG. 39.

FIG. 42 is a front view of a wedge.

FIG. 43 is a perspective view of the wedge shown in FIG. 42.

FIG. 44 is a perspective view of a cap.

FIG. 45 is a side view of the locking member, wedge, cap and actuatingmember in an assembled position.

FIG. 46 is a view of operating member, actuating member and the wedge inan assembled position.

DETAILED DESCRIPTION

The device shown in FIG. 1 is the handle of an implement comprising aninner element 1 with hole 2 for attachment of a suitable implement. Theinner element 1 is fitted into an outer element 3 with a certainclearance. In this case the inner and out elements 1 and 3,respectively, are tubular with suitable diameters and are thus turnablein relation to each other. The inner element 1 is detachably locked tothe outer element 3 with the aid of a locking member 4. When notactuated the locking member 4 is locked by spring elements, the functionof which will be further explained later in the description. A handle isfitted over the top of the outer element 3, below which an operatingmember 5 is turnably attached. Compression of the operating member 5 inthe direction of the arrow J releases the locking device 4 and the innerelement 1 can then be turned and displaced in relation to the outerelement 3. It is thus possible to adjust the handle of the implement tothe desired length and also to turn the implement to the desired anglewithout the operator having to bend down. In practice adjustment of thehandle is effected by the operator moving his/her hand down from thegripping handle 6 and pressing the operating member 5 towards the outerelement 3. Thanks to the placing of the operating member 5 in the upperpart of the handle of the implement, the operator need not bend his/herwrist during operation.

Furthermore, only one hand is required for the adjustment since, uponcompression of the operating member 5 in the direction of the arrow J,the hand will also grip the outer element 3. The properties describedabove are of great benefit to those who frequently use such implementswith handles. One such occupational category is cleaning staff who spendmost of their working hours using cleaning handles, the length of whichmust frequently be adjusted.

The device in accordance with the invention consists of three logicalunits: the locking member, the operating member, and an actuating membertherebetween via which actuation of the operating member is transmittedto the locking member. One of the aims of the invention has been toachieve reliable locking with small operating force and short operatingdistance. This aim is achieved with an embodiment of the locking deviceas shown in FIGS. 2 and 3. The locking member 4 here consists of apartially slotted rod, suitably of reinforced plastic, which is whole atthe top and forms an attachment collar 10, the latter being permanentlyconnected to the outer element 3. The lower part 8 of the rod is partlyseparated from the upper part by a slot 17, the depth of the slot beingsuch that a relatively narrow neck connects the upper part 10 and thelower part 8. The lower part 8 is cleft in axial direction by awedge-shaped groove 13 and thus forms two jaws 9 that are radiallydisplaceable. Friction pads 12 are fixed on the inside of these jaws 9,the pads being shaped to the envelope surface of the inner element.These friction pads 12 may suitably be made of rubber and can be tapedto the inside of the jaws 9, or of a rubber profile with ridges that canbe inserted into corresponding grooves in the jaws 9 (not shown in thedrawing). The jaws 9 are pressed with relatively strong force by thespring elements 11 against the inner element 1 which is thus lockedagainst the outer element 3 via the friction pads 12. A wedge 14 fitsinto the groove 13 and is in connection with an actuating member 7. Thiswedge 14 slides against the opposing edges in the groove 13. The anglebetween these edges is so large that self-locking of the wedge cannotoccur and, when not actuated by the operating member 5, this wedge 14 isalways in the lower position as shown in FIG. 2. FIGS. 4 and 5 show thelocking device 4 when disconnected.

Under the influence of an operating force from the operating member 5the actuating member 7 is drawn in the direction of the arrow F. Thewedge 14 is thus drawn in the direction of the arrow G into the groove19 in the attachment collar 10. This groove 19 also runs through theouter element 3 so that the wedge 14 can be freely drawn in thedirection of the arrow G. The wedge-shaped groove 13 is thus separatedin tangential direction as indicated by the arrows H. A small gap thusappears between the friction pads 12 and the inner element 1 so thatthis can easily be displaced in relation to the outer element 3 in thedirection of the arrows I, and can also be rotated. Under the influenceof the operating force the lower part 8 tends to bend and must thereforebe support by a peg 18 in the slot 17. Said peg 18 is rigidly attachedto one of the jaws 9 and, during the operation, slides against the edgeof the attachment collar 10. The wedge 14 is provided with internal andexternal guiding edges 22,21, respectively, which keep the wedge inplace in the groove 13. For the sake of clarity the lower part of theexternal guiding edge 21 is not shown in FIGS. 2 and 4. Operation of thelocking member 4 is thus performed via an actuating member 7.

The actuating member 7 preferably comprises a thin tape for which thereis room in the narrow tap between the inner element 1 and the outerelement 3, which is extremely advantageous. The tape may be made ofhigh-quality reinforced plastic, but is preferably made of high-strengthspring steel which is commercially available in desired widths down to athickness of 0.2 mm. The advantages of such a steel tape are that it isstrong and flexible but relatively inelastic upon tensile stress.

The steel tape is bent perpendicularly outwards, fitted into athrough-slot 16 in the wedge 14 and bent downwards on the upper side ofthe wedge 14. A through-hole is provided at the lower end of the steeltape, into which the attachment screw 15 is fitted and screwed into thewedge 14. The spring elements 11 preferably consist of rings of springsteel which are standard products. The advantages of this type of springelement are that they produce a compact construction and that theyenclose the jaws, thereby supporting the jaws 9 along the entireenvelope surface below which the friction pads 12 are secured. Thefriction pads 12 can thus be pressed against the inner element 1 from along time without causing any deformation in the jaws 9 that mightimpair the locking function.

FIG. 6 shows a view, partly in cross-section, of a preferred embodimentof the invention. To save space the outer element 3 is shortened hereand the operating member 5 is therefore a shorter distance from thelocking member 4 than is shown in FIG. 1. The tongue 51 of the operatingmember 5 fits into slots in the outer element. This tongue 5 isconsiderably narrower than the inner diameter of the outer rod and isprovided with a groove 55 riding on a lower edge 54 of the upper grooveof the outer element 3. The operating member 5 can thus be turned aroundthe edge 54 in the direction of the arrow J. During this rotation theportion 52 is moved in towards the free space 58 inside the outerelement 3 and forms a stop against the upper edge of the inner elementso that this cannot prevent rotation due to wedging. For the same reasonthe portion 52 comprises an outwardly directed shoulder 53 which, whenthe operating member is inactive, protrudes through a lower slot in theouter element 3.

When the operating member 5 is turned towards its stop position theshoulder 53 is in such a position that it stops the inner element 1 sothat this cannot prevent rotation by wedging. The operating member 5also comprises a wider grip 57 for comfortable operation. The actuatingmember 7 is attached in the operating member and in this embodiment isin the form of a steel tape screwed to the operating member by means ofthe screw 56. The steel tape rests against the edge of the operatingmember 5 and follows this edge in towards the innermost edge of thetongue 51, shaped with a radius. When the operating member 5 iscompressed in the direction of the arrow J, the tongue 51 is rotatedupwards towards the gripping handle 6. The steel tape is thus pulled inthe direction of the arrow F and the wedge 14 in the direction of thearrow G. The inner element 1 is thereby disconnected from the outerelement 3 and can be freely displaced and rotated in relation theretowithout being impeded by the actuating member 7 since this is so narrowthat it only marginally fills the gap between the inner and outerelements 1 and 3, respectively.

Practical tests have shown that if the operating member 5 is actuatedwith a compressive force of 25 N for an operating distance of 30 mm, anextremely reliable locking function can be released, thereby resultingin very convenient operation for the operator. Instead of hooking theoperating member in the edge 55 of the outer element 3 it would also bepossible to store the tongue 51 of the operating member 5 in a shaftrunning through the hollow in the centre of the outer element 3. Thisresults in a smaller lever and the angle of rotation will becorrespondingly greater.

FIG. 7 shows an embodiment of the operating member 5 having theadvantage of not intruding into the outer element 3 and therefore notstopping the inner element 1, which can thus be freely pushed past theoperating member 5 to the desired position. The operating member 5 ishere turnably journalled in a yoke 25 via the axis 26. The yoke 25partially surrounds the outer element 3 and is rigidly connectedthereto. The actuating member 7 protrudes through a slot 27 in theenvelope surface of the outer element 3.

FIGS. 8 and 9 show an embodiment of the invention in which the actuatingmember 7 is omitted. The operating member 5 comprises a U-shaped sectionpartially surrounding the locking member 4 with two flanges 61, twocircular pins 60 being attached on the inside of one of the flanges. Apin is rigidly attached on the inside of the opposite flange, on a levelexactly between the pins 60, fitted into corresponding holes in the rearof the lower part 8. This opposing pin, which is thus hidden in thefigures, defines the centre of rotation upon compression of theoperating member 5. Pins 60 are fitted into corresponding semi-circulargrooves 62 in opposing edges of both jaws 9. Under the influence of acompressive movement of the operating member 5 in the direction of thearrow J, the wedge-shaped groove 13 is separated in tangential directionin the direction of the arrows H. A small gap thus appears between thefriction pads 12 and the inner element 1, whereupon this can easily bedisplaced in relation to the outer element 3 in the direction of thearrows I, and can also be rotated. This embodiment has the advantage ofbeing cheaper to manufacture and gives an very reliable and easilyoperated disconnection if operation need not occur at a distance fromthe locking member.

In the above description the invention has been applied to the handle ofan implement. However, it can naturally be applied in all areas in whichelements need to be telescopically displaced and rotated in relation toeach other. The same inventive concept, with an operating member placedat a distance from the locking device, can be applied to other types oflocking members than those described above. However, it is preferablefor the locking device to be locked under influence of the springelement. The desired displacement of the jaws 9 may also be achieved inmany other ways besides those described above. In the above descriptionthe jaws 9 are connected by a neck to an attachment collar 10. However,the jaws 9 can naturally be displaceably attached to the outer element 3in some other way, e.g. they may consist of separate parts inserted intorectangular grooves in the outer element 3, or made in one piece withthe outer element. The spring elements 11 may, furthermore, be designedin widely different ways and still give the same compressive function.The invention has been described above as applied to rods and pipes withcircular cross section. The same inventive concept can naturally also beapplied to rods and pipes with other cross sections, e.g. rectangular.The invention can also be varied within the scope of the claims in waysobvious to one skilled in the art.

The invention can be further varied within the scope of the claims asfollows: FIGS. 10,11,12 show partial views of an embodiment of theinvention where the actuating member 7 is omitted. The operating member5 comprises a U-shaped section which partially surrounds the attachmentcollar 10 of the locking member 4 with two flanges 61.

Holes are arranged in the flanges for trunnion pins 70 that are attachedin the envelope surface of the attachment collar 10. These trunnion pins70 define the centre of rotation upon compression of the operatingmember 5. Furthermore, as previously, two radially displaceable jaws 9are arranged to be opened under the influence of the wedge 14. The wedge14 is provided with an upwardly directed extension 73 which engages in adriving slot (not shown) in the interior of the operating member 5. Asplit washer 72 fulfils the same function as the peg 18 describedearlier. The lower part of the locking member 4 is covered by a cap 71,shown in section in FIGS. 12 and 13. The cap fits against the supportflanges 73. FIG. 12 shows the locking device in disconnected position.The operating member 5 has been turned about the trunnion pins 70 bymeans of a compressive force J against the outer element 3.

The upwardly directed extension 73 of the wedge 14 is thus drawn upwardsin the figure and the wedge 14 has thus released the locking device sothat the inner element 1 can move freely in relation to the outerelement 3.

FIGS. 13 and 14 show another embodiment of the invention. The innerelement 1 is here turned to face the operator and the lower end of theouter element 3 forms an attachment for an implement through a hole 2.The locking member 4 is secured in the lower part of the inner element 1and fitted into the outer element 3. The locking device 4 comprisesradially displaceable jaws 9 provided externally with friction pads.These are pressed outwards by spring elements so that the inner element1 is locked against the outer element 3. Neither the friction pads northe spring elements are shown in the figure. Influenced by a wedge 14with two oppositely facing, angled sliding surfaces fittingcorresponding oppositely facing sliding surfaces on the inside of eachjaw 9. An actuating member 7 is attached to one part of the wedge 14.

This actuating member 7 is fitted into the inner element and no space istherefore required for it between the inner and outer elements, thusfacilitating assembly. The actuating member 7 is attached by its otherend to the operating member 5. When the operating member 5 is moved inthe direction of the arrow J, the actuating member 7 is drawn in thedirection of the arrow F and the wedge 14 presses the jaws 9 together,thereby releasing the locking member. The locking member 4 may naturallybe designed in many ways within the scope of the inventive concept.

FIGS. 15,16 and 17 show yet another embodiment of the invention.

The locking member 4 here comprises a housing 81 in which a lockingwedge 82 and a lever 85 are pivotably journalled via pins 83 and 86.

Influenced by a spring 84 the locking wedge is pressed againstcorresponding wedge-shaped grooves in the inner element 1. The lockingforce can be varied as desired depending on the wedge angle.

When the actuating member 7 is drawn in the direction of the arrow F,the lever 85 is turned so that the protruding piece 87 presses down theprotruding piece 88 in the locking wedge 82. The locking wedge 82 isthus drawn out of the wedge-shaped slot 80 in the direction of the arrowG, and the inner rod is freely movable in axial direction. This type oflocking member 4 can thus also be operated by an operating member at thedesired distance.

The inventive concept of operation being performed at a distance fromthe locking member can naturally be applied to many different types oflocks, including shape-dependent locks in accordance with FIG. 18 wherea number of rectangular holes 89 are arranged in an axially directedrecess in the inner element 1, similar to the wedge-shaped groove 80 inFIG. 17. A pivotable lock catch 82 can cooperate with the desired hole89 so that stepwise control of the axial position between the innerelement 1 and the outer element 3 can be achieved with an arrangementhaving a lever 85 etc, similar to that shown in FIGS. 15 and 16. Thistype of lock can be varied in many ways, such as by replacing the holes89 with grooves produced by a press operation, for instance. Theadvantage of shape-dependent locks is that they are generally cheaper tomanufacture and require considerably less operating force thanfriction-dependent locks.

Most known locks for telescopically displaceable elements are based onthe principle of radially displaceable locking elements applying forceon the inner rod.

FIGS. 19-38 show variants on the principle of applying force on theinner rod by means of tangentially displaceable locking elements. Theadvantage of this is that the locking forces are greater, due to thewedge action, despite relatively small operating force.

FIGS. 19 and 20 show an inner rod 1 surrounded by a locking housing 102in which locking elements 103 can be displaced tangentially towards theinner rod. Thanks to the angles a wedging action is obtained such thatthe locking forces FL are greater than the operating forces FM.

FIG. 21 shows a locking yoke 112 having locking surfaces 103. Thelocking yoke is inset in a recess in an outer rod 102. The inner rod isthus locked against the locking surfaces 103 and the opposing innersurface of the outer rod when the locking yoke 112 is moved to the leftin the figure.

FIG. 22 shows a locking yoke 112 based on the same principle as in FIG.21. The locking yoke is operated by a knob 115 with an inclined contactsurface against the outer rod.

FIGS. 23 and 24 show the outer rod of a section with integrated lockingelement 103. The inner rod is pressed against the locking surfaces bythe inclined contact surface of the operating knob 115 via recesses 113in the outer rod.

FIG. 25 shows the contact surface of the knob 115.

FIGS. 26-28 show an outer rod 102 with integrated locking elements 103.

FIG. 29 shows how the locking elements 103 can be pressed/embosseddirectly in the outer rod or shaped as separate elements 104 in adifferent material, e.g. rubber which can be inserted into groovespunched out in the outer rod.

FIGS. 30-32 show an outer rod with a part 104 having flaps 105 punchedout. Locking elements 103 are pressed into these and operating holespunched out.

FIGS. 33-35 show a locking device with outer rod 102 as shown in FIGS.30-32, an inner rod 1 and an operating member 108 with lever 117. Theoperating member 108 is provided with two pins 109 operating in holes106. The pins 109 are located on one flange 116 of the member 108. Onthe opposite flange is a guide pin 110 that operates in a guide hole inthe outer rod. A compression spring 111 is tensioned between the outerrod 2 and the lever 117. The operating member 108 is moved in thedirection of the arrow A, whereupon the flaps 105 are drawn towards eachother by the pins 109 and the locking elements 103 are pushed intangential direction towards the inner rod which is thus clamped withconsiderable force. The lock is opened by pressing the lever 117 of thelocking device towards the outer rod.

FIGS. 36-38 show an alternative embodiment of the device illustrated inFIGS. 33-35. In FIG. 36 the operating member is in unlocked position andthe inner rod 1 can move freely in relation to the outer rod 102. Theoperating member 108 is connected as above to the outer rod 102 via pinsacting in operating holes. When the lever 117 of the operating member108 is pressed in the direction of the arrow A, the inner rod 1 isclamped tightly in the same way as above. Operation of the blockingmember 120 blocks the operating member in locked position. The blockingmember comprises a catch 121 and spring flaps 123, one of each side ofthe outer rod, which are attached on a tubular part 124 surrounding theouter rod. The blocking member 120 also comprises an operating lever122. The blocking member, like the operating member, is suitablymanufactured from injection-moulded reinforced plastic. A springfunction is thus easily achieved in the flaps 123. This blocking membermany be designed in many ways. It may, for instance, be provided withseveral catches permitting selection of the desired locking force.However, it is desirable for a locked position to give sufficientlocking force regardless of normal variations in rod dimensions. This isenabled by the elasticity of the punched flaps 105 so that a certainresilience arises that prevents any variations in rod dimensions fromaffecting the locking function. The lock is easily opened by pressingthe operating lever 122 in the direction of the arrow B. This embodimenthas the advantage of requiring little space in its normal, lockedposition since the operating lever 108 is pressed against the outer rod.

FIGS. 39-46 show preferred embodiments of components of the invention,in which, FIG. 39 illustrates a locking member seen from the front, FIG.40 illustrates the locking member in accordance with FIG. 39 seen inperspective, FIG. 41 illustrates a cross-section through the lockingmember in accordance with FIG. 39 along the line A-A, FIG. 42illustrates a wedge seen from the front, FIG. 43 illustrates the wedgein accordance with FIG. 42 seen in perspective, FIG. 44 illustrates acap seen in perspective, FIG. 45 illustrates locking member, wedge, thecap in section, and actuating member when assembled, FIG. 46 illustratesoperating member, actuating member and wedge, with the operating memberin section.

The function of the embodiment of the locking member 4 in FIGS. 39, 40and 41 is particularly good. The upper part comprises an attachmentcollar 10 as previously. The lower part 8 comprises two jaws 9, theinner surface of which shall be provided with friction pads 12 and theouter surface of which constitutes a support surface for spring elements11. These components 12 and 11 are not shown in the figures butpreferably consist of self-adhesive rubber sheet and split rings ofspring steel, respectively, as described earlier. It is particularlyfavourable for the support surfaces of the jaws 9 for these spring steelrings 11 to be slightly elliptical as shown in FIG. 41 so that the smallaxis Q of the ellipse runs through the wedge-shaped groove 13 and thusthrough the open part of the steel rings 11. Such a design allows thepressure from the spring elements 11 to be distributed uniformly acrossthe circumference and the locking effect is therefore greater since agreater area of the rubber sheet 12 is engaged. It is also favourable tohave a relatively large wedge angle in the groove 13 since less of theoperating force is then required to overcome the friction and the degreeof efficiency is therefore greater. However, a larger wedge angle alsomeans that the length of the wedge will be less since the steel rings 11must encompass a larger part of the envelope surface of the jaws inorder to obtain the required locking force. A satisfactory openingfunction also requires the separating force from the wedge 14 to bedistributed over as long an axial distance on the jaws 9 as possible.This problem is solved with an embodiment in which the separating forceis achieved by two or more wedge elements. The figures show how thegroove 13 has been provided with two pairs of facing wedge surfaces 203with relatively large wedge angle, so that the separating force on thejaws 9 is distributed over a longer axial distance that would have beenpossible with one wedge element and one pair of wedge surfaces. A wedge14 as shown in FIGS. 42 and 43 is provided on its lower side with twowedge elements having two pairs of outwardly facing wedge surfaces 204.These wedge surfaces cooperate with the wedge surfaces 203 of the groove13 when the wedge 14 is displaced upwards in axial direction andextremely good opening function is achieved. FIGS. 42 and 43 also show anut recess 205 for receiving a square nut and a helicoidal groove 206,said helicoidal groove 206 running through the wedge 14 from the nutrecess 205 up to the upper wedge element in axial direction. Thehelicoidal groove 206 is open at the top in its lower part of the wedgeand open at the bottom in its upper part. These two grooves 205 and 206in the wedge 14, together with a combination of screw and nut, enablethe position of the wedge to be adjusted to suitable engagement with thegroove 13 in the locking member 4, as will be described in more detailbelow.

FIG. 44 shows a cap 71 designed to be fitted over the locking member 4.The main function of the cap 71 is to protect the locking device withits cooperating parts, but also to give the construction a betterdesign.

The cap 71 also has an important function in supporting the wedge 14 sothat it cannot fall out of the groove 13. This is shown in FIG. 45 wherethe cap 71 is shown in section, fitted onto the support rings 212, 213and 214 of the attachment collar 10. The inner surface of the cap 71thus supports the outer surface 207 of the wedge 14 with a certainclearance so that the wedge 14 can slide axially in the groove 13without falling out of the groove. The advantage of this is that thewedge 14 may have much simpler geometry since no outwardly facing guideedges 22 as in FIG. 3 are needed. FIG. 45 shows an actuating member 7 inthe form of a steel tape with a hole in the lower part, passed over ascrew 201. The actuating member 7 is bent over a nut 200, the nut beingscrewed onto the screw 201 and fitting partially into the nut recess205. The screw 201 is inserted into the groove 206 in the wedge 14 asdescribed earlier, and rests against an edge in the bottom of the hole.Turning the screw 201 causes the nut 200 to move in axial directionsince the nut recess 205 and actuating member 7 prevent the nut fromrotating with the screw. The cap 71 is provided with a hole 202 where ascrewdriver can be inserted for adjustment of the screw 201. Thisarrangement allows the position of the actuating member 7 to be easilychanged in relation to the wedge and the wedge 14 can be adjusted tosuitable engagement with the groove 13. For the sake of clarity thewasher 72 to be fitted into the groove 17 has not been shown in FIG. 45,nor the inner and outer elements.

FIG. 46 shows how the wedge 14 cooperates with the operating member 5via the actuating member 7. The operating member, shown incross-section, is suspended in a shaft 26 threaded through holes in theouter element 3. The operating member is partially inserted into thegroove 209 in the outer element. The lower part of the operating memberis provided with a hole for the shaft 26, said hole defining the centreof rotation. Above the hole the operating member has a curved, outwardlydirected surface 211 with large radius, for receiving the upper part ofthe actuating member 7. This actuating member 7 is provided with a holein its upper part for the screw 208 which is screwed into acorresponding hole in the operating member. To disconnect the lock thegripping surface of the operating member 5 is pressed against the outerelement 3 in the direction of the arrow J. The screw 208 is thus rotatedand the actuating member 7 is drawn upwards in the direction of thearrow F so that its upper part is bent over the surface 211. Since thishas a large radius, no damaging bending stresses occur in the actuatingmember 7. When the actuating member 7 is drawn in the direction of thearrow F, the wedge 14 is drawn in the same direction and the jaws 9 ofthe locking member 4 are separated due to the action of the wedgesurfaces 204 and the lock is released as described earlier. By turningthe screw 201 the position of the wedge 14 in relation to the actuatingmember can be altered in the direction of the arrow P as describedearlier.

This arrangement with a pulling actuating member is advantageous sinceit can be in the form of a thin tape with no buckling problems. It canalso easily be adjusted to a suitable tension through the above design.An actuating member protruding in the form of a rod having across-section that will withstand buckling is also possible, or a rod ina supporting groove. This supporting groove may be integrated with theouter element and possibly be half-open, with the opening towards theinside or the outside of the outer element. Such an outer element caneasily be manufactured in the form of an aluminium section.

However, it is inevitable that a protruding actuating member 7 willrequire more material and more space, at least with the preferred typesof lock where relatively great forces are transmitted.

If shape-dependent lock types are to be used, as in FIG. 18, forinstance, a protruding actuating member might be preferably since theoperating forces may then be considerably lower.

The embodiments with pulling or pushing actuating members have in commonthat the actuating member 7 is displaceable along the longitudinal axisof the outer element 3.

It is also possible for the operating force to be transmitted by theactuating member being turned about a shaft parallel with thelongitudinal axis of the outer element 3. The actuating member mightthen be a round rod inserted in a groove in the outer element, or a pipebetween the inner element 1 and the outer element 3.

Common to these variants of the invention is that the outer element 3 isprovided at one end with a locking device 4 and an operating member 5spaced from the locking device 4 towards the other end of the outerelement.

While the present invention has been described in accordance withpreferred compositions and embodiments, it is to be understood thatcertain substitutions and alterations may be made thereto withoutdeparting from the spirit and scope of the following claims.

1. A locking device comprising: an inner element and an outer element,the inner element having a lower free end being extendable and axiallymovable from a first end of the outer element in a first direction, theinner element being slidable inside the outer element, a locking memberfor locking the inner element relative to the outer element, anactuating member extending in a second direction away from the first endof the outer element towards a second opposite end of the outer element,the actuating member extending along the outer element, the seconddirection being opposite the first direction, an operating member inoperative engagement with the actuating member and remote from thelocking member, the locking member being operable by the operatingmember via the actuating member, the actuating member being displaceablealong, or turnable about, an axis substantially parallel with alongitudinal axis of the outer element, the locking member having alocking surface biased to the inner element by a spring elementproviding a biasing force in a radial direction, the biasing forcebiasing the locking surface to the inner element is constant orincreased when the inner element being pressed in the second directionrelative the outer element.
 2. A locking device, comprising: a firstelement and a second element, the first element being displaceablerelative to the second element, a locking member disposed at a first endof the second element the locking member having one or more radiallydisplaceable tongue members that are contactable with a contact surfaceof the first element, the tongue members being biased towards the firstelement by a spring element providing a biasing force in a radialdirection, the tongue members comprising surfaces cooperating with anengaging member for releasing a contact between the tongue members andthe contact surface of the first element, the surfaces beingsubstantially tangentially directed.
 3. A locking device as claimed inclaim 2 wherein the engaging member comprises a wedge.